Process of making cement.



grinding the separate ingredients.

UNITED STATES QATENT OFFICE.

HENRIK EMIL RIlSAGER, OF FREDERIKSBERG, NEAR COPENHAGEN, DENMARK.

PROCESS OF MAKING CEMENT.

SPECIFICATION forming part of Letters Patent No. 718,729, dated January20, 1903.

Application filed February 9, 1901. Serial No. 46,716. (No specimens.)

To all whom it may concern:

Be it known that I, HENRIK EMIL Rt'isAGER, of Frederiksberg, in theKingdom of Denmark, have invented certain new and useful Improvements inProcesses of Making Cement, of which the following is a specification.

The object of this invention is to provide a simple and economicalprocess of making cement; and for this purpose the invention consists inthe steps of grinding separately the ingredients of the cement in theirnatural humid state, simultaneously grinding and mixing said groundingredients together in the presence of a limited quantity of water,calcining the resulting sludge to clinker, and pulverizing said clinker.

In carrying out the process the first step is The raw materials aresubjected in their natural humid state in which they are quarried or dugand without artificial drying to this preliminary reduction, which iscarried as far as the natural qualities of the materials themselvespermit. The ground raw materials are then mixed and ground together.This operation is accomplished in the presence of a Very limitedquantity of watersay one part to every three parts of solid matterandthis operation of simultaneous mixing and grinding together isadvantageously effected in tubular ball-mills. The result is a thickdense sludge in which the constituents are extremely finely subdividedand homogeneously and intimately mixed. This sludge is then dried andburned (calcined) into clinker. The clinker is then ground to animpalpable'powder and forms the product of the process.

This process carried out inactual manufacture and on a large scale hasdemonstrated that even in the case of raw materials the hardest and mostdifficult to work a most finely subdivided and homogeneous product isobtained under a consumption of power approximately one-half thatnecessary for obtaining even a tolerably good result by the dry processas heretofore commonly carried on. By the operation of grinding andmixing the raw materials into a paste or sludge the small particles arebrought so closely in contact and are so intimately mixed that thechemical reaction is easily and perfectly accomplished, the pasteshrinking as the moisture evaporates and bringing the particles of thedifferent constituents in close mutual contact. As compared with the dryprocess heretofore employed the preliminary drying of the raw materialsis avoided, a better and more intimate mixing of the constituents isobtained, by which the quality of the cement is greatly improved, andgreat economy in power and fuel consumption is obtained. As comparedwith the well-known wet process there is a very great saving in fuel andlabor.

In case one of the raw materials is soluble in water it may be dissolvedin the water added to the other materials in the ball-mill instead ofbeing introduced therein in powder form, thus facilitating the reaction.

Having thus described my invention, I claim as new and desire to secureby Letters Patent- 1. The process herein described of making cement,which consists in grinding separately the raw ingredients in theirnatural, humid state, into a powder as fine as the moisture present willreasonably permit, simultaneously grinding and mixing the thuscoarselygronnd ingredients together in the presence of a small quantityof water sufficient to form a sludge of a creamy consistency, calciningthe said sludge to clinker, and pulverizing said clinker, substantiallyas set forth.

2. The process herein described of making cement which consists ingrinding separately the raw ingredients in their natural, humid state,dissolving one of said ingredients in a small quantity of water,simultaneously grinding and mixing the remaining ingredients with saidsolution so as to form a sludge of a creamy consistency, calcining theresulting sludge to clinker and pulverizing the said clinker,substantially as set forth.

In testimony that I claim the foregoing as my invention I have signed myname in presence of two subscribing witnesses.

I-IENRIK EMIL RtisAeER.

Witnesses:

ERNEST BOUTARD, P. HOFMAN BANG.

Afiidavit having been filed showing that the name of the patentee inLetters Patent No. 718,729, granted January 20,1903, for an improvementin Processes of Making Cement, should have been Written and printedHenrik Emil Riz'sager instead of Henrik Emil Rusager, it is herebycertified that the proper correction has been made in the files andrecords pertaining to the case in the Patent Office, and should be readin the Letters Patent that the same may conform thereto.

Signed and sealed this 31st day of March, A. D., 1903.

[SEAL] F. I. ALLEN,

Commissioner of Patents.

